This invention relates to a binding agent useful for coloring textile substrates such as upholstery fabric, apparel/garments, towels, sheets, drapery, etc., and its method of use.
It is known that various textile substrates can be colored (e.g., printed or pad dyed) with aqueous print pastes and dyebaths comprising pigments, dyestuffs, binding agents, thickeners and other additives. The binding agent is typically utilized to provide improved crockfastness and wash fastness properties, and resistance in some instances to degradation due to UV exposure.
The binding agent is also required to bind the pigments and dyes to the textile substrate. The binding agents are typically polymeric dispersions or emulsions which undergo crosslinking under the conditions used to fix the dye or pigment. An exemplary binding agent system is one based on self-crosslinking acrylic copolymers containing N-methyol acrylamide or N-methyol methacrylamide. For example, U.S. Pat. No. 4,309,179 to Heuser et al. proposes a binding agent comprising an acrylic resin terpolymer containing 30 to 55 percent by weight styrene, 20 to 35 percent by weight acrylic acid or methacrylic acid, and 15 to 40 percent by weight of N-methylol acrylamide or N-methylol methacrylamide; a water soluble melamine-formaldehyde aminoplast; and, an elastomeric latex. See, also for example, U.S. Pat. Nos. 3,878,151 to Dachs et al. and 4,331,752 Tomasi et al.
Binding agents can also be based on butadiene, styrene, and nitrile monomers and copolymers thereof, with each other and other copolymerizable monomers. For example, U.S. Pat. No. 3,223,663 to Altobelli et al. proposes a binding agent system based on a carboxylated elastomeric polymer including 1 to 5 percent acrylic acid, methacrylic acid or itaconic acid.
The binding agent should be compatible with the conventional components of the textile print paste and should not adversely effect the fastness of the print or the dye yield thereof. In the case of print pastes prepared using a binding agent derived from acrylonitrile such as a butadiene/acrylonitrile copolymer, desirable wash fastness and crockfastness properties can be obtained but exposure to UV irradiation can cause significant yellowing. Binding agents derived from acrylic polymers tend to be resistant to UV irradiation but have somewhat inferior crockfastness properties as compared to binding agents derived from nitrile-based polymers.
It is therefore an object of the present invention to provide a textile coloring agent or medium and binding agent thereof contributes to desirable crockfastness and washfastness properties and is resistant to yellowing and degradation on exposure to UV light.